What is the "11 hour runtime" based on? A 6ah 20v battery on high (5000 lumens) or a 5ah 20v battery on low (??? lumens)? Why is there an asterisk following the 11 hour runtime claim if there is no footnote explaining the asterisk?!?!?

Using DCB206 6.0Ah 20V MAX Lithium Ion battery on low setting.